1. Field of the Invention
The present invention relates to a data record medium, a recording apparatus, a reproducing apparatus, and a reproducing method that allow addresses corresponding to a high density structure to be displayed.
2. Description of the Related Art
As a record medium on which audio data is digitized and optically recorded, a compact disc (CD) is well known. A CD has a diameter of 12 cm, a track as pitch of 1.6 xcexcm, and a line velocity of 1.2 m/s. On a CD, digital audio data of up to 74.7 minutes can be recorded. When the track pitch of a CD is as narrow as 1.5 xcexcm as the narrowest pitch defined in its standard, digital audio data of around 80 minutes can be recorded.
In addition, as a read-only record medium, a CD-ROM of which a CD is applied to a ROM (Read Only Memory) in such a manner that digital data other than digital audio data is pre-recorded to an audio record area of the CD has become common. In the same standard as a CD, digital data of 650 Mbytes or more equivalent to digital audio data of 74.7 minutes can be recorded to a CD-ROM.
Each of a CD and a CD-ROM has a sub code composed of eight channels (P, Q, R, S, T, U, V, and W channels). Time information of digital data that is recorded is placed in 72 bits of the Q channel. The time information is categorized as two types of reproduction elapsed time referred to as absolute time and relative time. The absolute time represents a time period from the beginning of the record area. The relative time represents a time period from the beginning of each music program or each index. Each of the two types of elapsed time is represented as minutes (MIN), seconds (SEC), and frames (FRAME) as time units. In a CD, the time information represents address information of digital data.
Each of the time units xe2x80x9cMINxe2x80x9d, xe2x80x9cSECxe2x80x9d, and xe2x80x9cFRAMExe2x80x9d is assigned data of eight bits and represented with a two-digit BCD (Binary Coded Decimal) number. Thus, in a CD and a CD-ROM, xe2x80x9cSECxe2x80x9d is represented from xe2x80x9c00xe2x80x9d to xe2x80x9c59xe2x80x9d in the BCD notation; xe2x80x9cFRAMExe2x80x9d is represented from xe2x80x9c00xe2x80x9d to xe2x80x9c74xe2x80x9d since one second is equivalent to 75 frames; and xe2x80x9cMINxe2x80x9d is represented from xe2x80x9c00xe2x80x9d to xe2x80x9c79xe2x80x9d because the recordable time period of digital data corresponding to the CD standard is less than 80 minutes (in other words, in the non-CD standard, xe2x80x9cMINxe2x80x9d is represented from xe2x80x9c00xe2x80x9d to xe2x80x9c99xe2x80x9d in the BCD notation).
On a CD-ROM, time information (address information) has been recorded to a header portion of main data as well as the Q channel. As with the Q channel, each of xe2x80x9cMINxe2x80x9d, xe2x80x9cSECxe2x80x9d, and xe2x80x9cFRAMExe2x80x9d is assigned data of eight bits and represented with a two-digit BCD number.
On a blank write-once-read-many type CD-R (CD-Recordable) disc and a rewritable type CD-RW (CD-Rewritable) disc, record address information referred to as ATIP (Absolute Time In Pre-grooves) is FM-modulated and recorded to guide grooves (pre-grooves) that are wobbled in the radius direction with a sine wave of 22.05 kHz in the format of xe2x80x9cMINxe2x80x9d, xe2x80x9cSECxe2x80x9d, and xe2x80x9cFRAMExe2x80x9d in the BCD notation.
As advancement of the pit forming technology and recording and/or reproducing technologies and achievement of short wavelengths of laser light, as with a DVD (Digital Versatile Disc or Digital Video Disc), the storage capacity of record mediums tends to increase. Thus, requirements of high density structures of conventional CD and CD-ROM are becoming strong.
When the record densities of the conventional CD and CD-ROM are doubled, digital data of around 150 minutes can be recorded. When their record densities are quadrupled, digital data of around 300 minutes can be recorded.
However, in the conventional CD and CD-ROM, as was described above, each of xe2x80x9cMINxe2x80x9d, xe2x80x9cSECxe2x80x9d, and xe2x80x9cFRAMExe2x80x9d that are time information is represented with a two-digit BCD number. Thus, the time information of the conventional CD-and-CD-POM cannot represent a time exceeding 100 minutes. As a result, the system does not work.
The present invention is made from the above-described point of view. An object of the present invention is to solve a problem of conventional CD and CD-ROM and provide a record medium that allows time information corresponding to a high density structure to be displayed with maintaining the compatibility thereof. In addition, to allow the present invention to be properly applied to a computer, address information of a CD-ROM and ATIP of a CD-R and a CD-RW are represented in the binary notation. Another object of the present invention is to provide a recording apparatus that records such time information to a record medium. A further object of the present invention is to provide a reproducing apparatus that reproduces such time information from a record medium.
To solve the above-described problem, a first aspect of the present invention is a data record medium for recording a digital signal composed of main data and a sub code, the sub code having time information representing reproduction elapsed time, the sub code being recorded in association with the main data, wherein the time information representing the reproduction elapsed time contained in the sub code has a sub code area represented with a binary coded decimal number, a header area for address information that is a part of the main data and that is in synchronization with the time information, and a data area for user data that is received from the outside as a part of the main data, the address information being represented with a binary number.
A second aspect of the present invention is a data record medium on which record address information as a guide for data has been recorded with a binary number, wherein the data record medium has a record area for main data and a sub code corresponding to the record address information, the sub code having time information representing reproduction elapsed time in a binary coded decimal notation in association with the main data.
A third aspect of the present invention is a recording apparatus for recording main data and a sub code to a data record medium, the sub code having time information representing reproduction elapsed time, the sub code being recorded in association with the main data, comprising: means for generating the time information with a binary coded decimal number;
converting means for converting the binary coded decimal number into a decimal number; and recording means for causing said converting means to convert address information contained in the main data and is in synchronization with the time information into a binary number and recording the resultant data along with the time information to the data record medium.
A fourth aspect of the present invention is a data recording apparatus for recording main data and a sub code to a data record medium, the sub code having time information representing reproduction elapsed time, the sub code being recorded in association with the main data, comprising: means for generating address information that is contained in the main data, is in synchronization with the time information, and is represented with a binary number; converting means for converting the binary number into a binary coded decimal number; and recording means for forming a sub code with the time information converted into the binary coded decimal number by said converting means and recording the sub code along with the main data to the data record medium.
A fifth aspect of the present invention is a data recording apparatus for recording data to a data record medium on which record address information for recording data have been formed with a binary number and the record address information has been assigned with guide grooves wobbled at predetermined intervals, comprising: reproducing means for reproducing the record address information from the data record medium; first recoding means for recording time information representing reproduction elapsed time of main data in synchronization with record address information reproduced by said reproducing means with a binary coded decimal number, the time information being in association with the main data; and second recording means for recording the main data.
A sixth aspect of the present invention is a reproducing apparatus for reproducing main data and a sub code from a data record medium, the sub code having time information representing reproduction elapsed time represented with a binary coded decimal number, the sub code being recorded in association with the main data, comprising: reproducing means for reproducing the main data and the sub code from the data record medium; first extracting means for extracting the time information from the sub code reproduced by said reproducing means; and second extracting means for extracting address information represented with a binary number from the main data reproduced from said reproducing means.
A seventh aspect of the present invention is a reproducing method for reproducing main data and a sub code from a data record medium, the sub code having time information representing reproduction elapsed time represented with a binary coded decimal number, the sub code being recorded in association with the main data, comprising the steps of: reproducing the main data and the sub code from the data record medium; extracting the time information from the sub code reproduced at the reproducing step; and extracting address information represented with a binary number from the main data reproduced at the reproducing step.
According to the present invention, for a data record medium such as a high density CD, in consideration of the compatibility with a conventional medium, when necessary, time information including hour information (HOUR) is represented in the BCD notation. For a data record medium such as a CD-ROM, in consideration with the harmonization with a personal computer, the notation of xe2x80x9cminutes, seconds, and framesxe2x80x9d is converted into the notation of xe2x80x9cframesxe2x80x9drepresented with a 24-bit (or 23-bit) binary number. For mediums such as a CD-R and a CR-RW, in consideration with the harmonization with a personal computer, ATIP is represented with a 24-bit (or 23-bit) binary number.